You’re sharing more on Facebook than you think

A new study by Carnegie Mellon University in Pittsburgh has found that Facebook users likely have increased the amount of information disclosed to both Facebook friends and “silent listeners,” a group that includes third-party apps, advertisers and Facebook Inc. itself.

The study, which was published in the Journal of Privacy and Confidentiality, found that between 2005 and 2009, users increased the amount of information shared with the public. However, in recent years, Facebook (NASDAQ: FB) users have decreased the amount of personal data shared publicly.

It’s the silent listeners that are seeing more information, the study found.

Third-party apps often create additional data points about a user that can be posted by the app on the user’s profile and transmitted to developers.

The study cited Spotify as an example. The app shows songs the user is listening to on the user’s profile.

Friends also have been able to add information about a user, including tagging photos and locations.

“Users ended up increasing their personal disclosures to other entities on the network,” the study said. “Sometimes, this occurred without users’ explicit consent or even awareness.”

The study’s researchers used data from 5,076 Facebook users in Carnegie Mellon’s network to gain a better idea of how privacy disclosures changed between 2005 and 2011.

In its conclusion, it wrote that some of its findings highlight the challenges users of social networks face when trying to manage online privacy and the power of providers of social media services to affect individuals’ disclosure and privacy behavior through default settings.